1. Field of the Invention
This invention relates to the field of articulating connecting rods and in particular to the generic species classified as intra-articulating systems.
2. Description of Prior Art
Intra-articulating connecting rods are most generally treated as independent or freely pivoting mechanisms. That is, the pivoting motion between the upper and lower connecting rod is independent of the construction or design of the associated linkage and therefore relies entirely on the system dynamics for actuation during the reciprocating process. The dynamic loads operating upon the system are a mixture of rotational and translational inertial forces acting at each end of the connecting rod. When the pivot point between the upper and lower connecting rod is located near the piston end the actuating forces are primarily translational in nature. When the pivot point is located at the other end of the connecting rod assembly, near the crankpin, the actuating forces are predominantly tangential and radial components of the crankshaft rotary motion.
I have discovered that the pivotal action between the upper and lower connecting rod is smoother when the system is weakly guided by a spring which supplies a tensile or compressive load between the two members. I prefer that this spring load be applied to some systems in a manner which tends to keep them in the untoggled configuration while in other systems I prefer the spring action to be applied in a manner which will tend to keep the system in the toggled configuration.
When the lower member of the connecting rod is designed as an eccentric, moving within the major journal of the upper connecting rod, the spring action can be provided by a flat or leaf type spring. The rotation can also be guided by coil or torsional springs. In either case the effect of the spring action upon the rotation of the eccentric within the connecting rod major journal is the same, that is, it reduces the tendency of the eccentric to flutter at each end of its travel.
In the starting operation of internal combustion engines the spring action provides a more positive force to the piston and therefore increases the reliability of ignition at the lower speed. In compressor and pump operations the spring action provides a smoother transitional period of acceleration during startup and shutdown and can be instrumental in the damping of resonant harmonic oscillations.